Serbia has detained a number of people over a suspected plot to sway the outcome of Montenegro’s Oct. 16 election, the Serbian prime minister said on Monday, citing “undeniable and material” evidence found by his country’s security services.Aleksandar Vucic’s remarks were the first detailed Serbian reaction to the arrests on election day in Montenegro of 20 Serbian citizens, including a retired police general, accused of planning attacks on government institutions and officials. The vote, in which veteran Prime Minister Milo Djukanovic’s party came out ahead but without a parliamentary majority, was billed as an opportunity for voters to endorse his pro-NATO and pro-EU stance instead of pursuing closer relationships with traditional allies like Serbia and Russia. Vucic told a news conference that the evidence found included 125,000 euros ($135,975) in cash and stashed uniforms that were to be used in attacks on Montenegrin state institutions and individuals. Supportive evidence had been given by detained suspects under questioning, he said.